Add V8 debugger agent....

src/flag-definitions.h

 // Copyright 2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 183 matching lines @@
 
 // usage-analyzer.cc
 DEFINE_bool(usage_computation, true, "compute variable usage counts")
 
 // v8.cc
 DEFINE_bool(preemption, false,
             "activate a 100ms timer that switches between V8 threads")
 
 // Regexp
 DEFINE_bool(trace_regexps, false, "trace regexp execution")
-DEFINE_bool(regexp_native, true, "use native code regexp implementation (IA32 only)")
+DEFINE_bool(regexp_native, true,
+            "use native code regexp implementation (IA32 only)")
 DEFINE_bool(regexp_optimization, true, "generate optimized regexp code")
 
 // Testing flags test/cctest/test-{flags,api,serialization}.cc
 DEFINE_bool(testing_bool_flag, true, "testing_bool_flag")
 DEFINE_int(testing_int_flag, 13, "testing_int_flag")
 DEFINE_float(testing_float_flag, 2.5, "float-flag")
 DEFINE_string(testing_string_flag, "Hello, world!", "string-flag")
 DEFINE_int(testing_prng_seed, 42, "Seed used for threading test randomness")
 #ifdef WIN32
 DEFINE_string(testing_serialization_file, "C:\\Windows\\Temp\\serdes",
               "file in which to testing_serialize heap")
 #else
 DEFINE_string(testing_serialization_file, "/tmp/serdes",
               "file in which to serialize heap")
 #endif
 
 //
 // Dev shell flags
 //
 
 DEFINE_bool(help, false, "Print usage message, including flags, on console")
 DEFINE_bool(dump_counters, false, "Dump counters on exit")
 DEFINE_bool(debugger, true, "Enable JavaScript debugger")
+DEFINE_bool(debugger_agent, false, "Enable debugger agent")
+DEFINE_int(debugger_port, 5858, "Port to use for remote debugging")
 DEFINE_string(map_counters, false, "Map counters to a file")
 DEFINE_args(js_arguments, JSArguments(),
             "Pass all remaining arguments to the script. Alias for \"--\".")
 
 //
 // Debug only flags
 //
 #undef FLAG
 #ifdef DEBUG
 #define FLAG FLAG_FULL
@@ skipping 115 matching lines @@
 #undef FLAG
 
 #undef DEFINE_bool
 #undef DEFINE_int
 #undef DEFINE_string
 
 #undef FLAG_MODE_DECLARE
 #undef FLAG_MODE_DEFINE
 #undef FLAG_MODE_DEFINE_DEFAULTS
 #undef FLAG_MODE_META